In 1252, Florence minted a gold coin: the fiorino d'oro, or florin.
It became the reserve currency of medieval Europe — stable, pure, trusted everywhere from London to Constantinople.
For 200 years it was the dollar of the medieval world.
Florentine banking families — the Bardi, the Peruzzi, the Acciaiuoli — grew into the most powerful financial institutions in the world.
When Edward III of England defaulted on his Bardi and Peruzzi debts in the 1340s, it triggered the first international banking crisis in European history.
The Medici learned the lesson: diversify, spread risk, never let any single client get too large.
The Florentines also invented the letter of credit — essentially the first cheque — which meant merchants could travel without carrying gold.
Fun fact: the word 'bank' comes from the Italian banca — the bench on which medieval money changers sat in the marketplace.
